Recently, various mobile communication services have been widely used, and service areas have been widely provided. In a mobile communication system of a Wideband Code Division Multiple Access (W-CDMA) method, high speed communication services of High Speed Downlink Packet Access (HSDPA) and the like have been widely applied as well as a service of a regular communication speed (called “regular service”). Also, a wireless Local Area Network (LAN), which realizes data communication with further high speed, is widely used. The wireless LAN service is regarded as a service of a public area, and service areas are scattered.
A mobile terminal supporting multiple communication services has mounted communication modules of respective communication methods for the communication services. In addition, in the above-described communication services, communication speed becomes higher with greater power consumption in a sequence of the regular service, the high speed communication service, and the wireless LAN service. Thus, the service area becomes smaller.
In the mobile terminal supporting the multiple communication services, a communication module supporting the multiple communication services searches for radio waves and determines whether communication is possible. It should be noted that in a case of being outside of communication range, since a random access outputting radio waves method in all directions is performed within a short period, the power consumption becomes greater.
In order to continue the communication in a case in which the communication is disabled while communicating with a base station, there is a “handover” method which changes a communication destination to another base station of the same communication method as the previous communication method before disabling of the communication and another “handover” which changes the communication destination to a base station of a different communication method from that used before disabling of the communication. In the “handover” methods, a communicable state with the communication destination may be always maintained to immediately switch the base station. As a result, the power consumption becomes greater. Also, in the latter “handover” method, communication disconnection may occur. Conventionally, the latter “handover” method is not conducted.
In a case in which the mobile terminal is located outside of the communication range, since the mobile terminal fails the handover while communicating with a server, after that, even if the mobile terminal comes back to the communication range, mostly the mobile terminal does not continue the communication at a service level. Even in a case in which the communication is possible to be continued, it may take time to resume the service. The mobile terminal takes time to detect being outside of the communication range due to weak radio waves. Since the server does not know a reason why it becomes impossible for the mobile terminal to communicate with the server, the server does not detect the communication disconnection until a time out.
In a known technology, a current location, a destination, a departure time, and an arrival time of a train are acquired from an IC tag of a communication terminal device at a train, and are transmitted to a base station apparatus. The base station apparatus estimates time when a user will exist in the service area, based on a distance from a current location to a service area boundary. Thus, it is possible to determine with high accuracy the service which a user is likely to select and successively receives until an end of the service.
In another technology, in a mobile terminal capable of communicating with both a first wireless communication system of a cellular method which covers a wide area and a second wireless communication system of a general hot spot method, detailed area location information of the second wireless communication system acquired from a base station is stored, and power wasted on area detection is prevented. Moreover, when communication speed of the mobile terminal is less than a threshold, communication with the first wireless communication system is maintained.